A. I can't believe it!
B. I can't believe it.
C. I can't believe it?
D. I can't believe it;
Answer: I can't believe it!
A. I can't believe it!
B. I can't believe it.
C. I can't believe it?
D. I can't believe it;
Answer: I can't believe it!
Additional Information: Exclamation marks indicate strong feelings or commands.
Subjects: Punctuation, Grammar